Answer:
2.247 grams per liter
Step-by-step explanation:
To calculate the density of a gas at STP, we need to convert the given conditions (temperature, pressure, volume, and mass) to STP conditions (0°C or 273.15 K and 1 atm or 101.3 kPa) using the ideal gas law.
First, let's convert the temperature from Celsius to Kelvin:
40.6°C + 273.15 = 313.75 K
Next, we need to convert the pressure from mmHg to atm:
710.9 mmHg * (1 atm / 760 mmHg) = 0.935 atm
Now, we can use the ideal gas law equation PV = nRT to calculate the number of moles of the gas.
P = Pressure in atm = 0.935 atm
V = Volume in liters = 1.69 L
n = Number of moles (to be determined)
R = Ideal gas constant = 0.0821 L·atm/(mol·K)
T = Temperature in Kelvin = 313.75 K
Rearranging the equation, we have n = PV / RT:
n = (0.935 atm * 1.69 L) / (0.0821 L·atm/(mol·K) * 313.75 K)
n = 0.0127 mol
Now, we can calculate the molar mass (M) of the gas using the given mass and the number of moles:
Molar mass (M) = Mass / Number of moles
M = 0.638 g / 0.0127 mol
M = 50.275 g/mol
Finally, we can calculate the density (d) of the gas at STP:
Density (d) = Molar mass / Molar volume at STP
d = (50.275 g/mol) / (22.4 L/mol)
d = 2.247 g/L
Therefore, the density of the gas at STP is approximately 2.247 grams per liter.